"There's not much point in trying to define an essay. Its parameters are so broad and slack that they encompass practically any shortish passage of non-fiction which makes a general argument.

"As a rough rule of thumb, I'd say anything that creeps over 40,000 words is entering book territory; and anything too autobiographical strays into memoir. But, still, you could write 50,000 words about yourself, and it could be an essay in every regard.

"It sounds banal, but all that matters is quality of writing and thought. Here are 10 that are exceptional in both departments."

Not an original choice of writer, or of essay. But it would be churlish not to include the man who, more than any other writer over the last century, fine-tuned the form. He applied his essayistic touch to an extreme variety of subjects – the ideal pub, school stories, what makes England England - but this one, on how he became a writer, is my favourite.

The word "intellectual" often brings a lot of dull baggage with it. But Orwell's honesty and humour mean that you're never in danger of being bored. His four reasons for writing - aesthetic enthusiasm, historical impulse, political purpose, sheer egoism - still seem unassailably true today.

You might call Gellhorn's account of Adolf Eichmann's trial in Jerusalem reportage. But that just shows up the flexibility of the essay. A routine bit of reportage remains reportage; brilliant reportage leaps its chains and becomes an essay.

Gellhorn's essay begins with a straight description of the conditions in the court, albeit an atmospheric, closely-observed description: "The air conditioning was too cold, and yet one sweated." But she constantly jumps from factual observation to general, philosophical thought. The seamlessly stitched combination of facts and thoughts becomes a compulsive essay.

Evelyn Waugh considered life as a printer, cabinet-maker and carpenter before becoming a novelist. He maintained an interest in the visual arts throughout his life; this plea in defence of the classical orders of architecture appeared some time after his literary success began.

The essay is full of angry argument, deep architectural knowledge and lyrical description. "The baroque has never had a place in England; its brief fashion was of short duration; it has been relegated to the holidays – a memory of the happy days in sunglasses, washing away the dust of the southern roads with heady southern wines."

You don't have to agree with the argument to be compelled by it – a rare thing in an essay.

Montaigne is regularly wheeled out as the father of the essay. Debatable, I'd say – the baggy definition of the essay includes much older works.

Still, as well as being early on the essay scene, Montaigne was a natural essay-writer. His essay on cannibalism introduces devices that crop up again and again among the essayists that followed through the centuries. Taking the cannibalism of the Tupinamba tribesmen of Brazil, he uses it as a general analogy for barbarism. "Every man calls barbarous anything he is not accustomed to," he writes, expanding the subject into a discussion on the ideas of primitivism, natural purity and perfection.

If you thought Steve Jobs's address to the graduating class of Stanford in 2005 was impressive, prepare to be even more deeply moved by Barrie's speech to the students of St Andrews University in 1922, where he had been voted rector.

Ostensibly about courage, the essay is really about how to deal with the loss of friends and brothers in the first world war; it's aimed at those "who still hear their cries [of the war dead] being blown across the links".

It opens up from the particular to the general, to the qualities needed to deal with such loss, and all with astonishing prescience: "By the time the next eruption comes it may be you who are responsible for it and your sons who are in the lava."

Capote is best remembered for his novels, but his non-fiction was exceptional: acidly witty, to the point of nastiness; hyper-observational, to the point of even deeper nastiness. But what is more enjoyable – or, often, truer – than nastiness?

This is the essay-as-interview - in this case with Marlon Brando, at the height of his fame. There's a good deal of nastiness, and racism – "You come see Marron?" says Capote's Japanese guide. But it also gives a rare insight into the perils of celebrity: of too big an entourage, of isolation, of too many appetites being too readily satisfied.

For dinner, Brando, on a diet, orders soup, beefsteak with French-fried potatoes, three supplementary vegetables, a side dish of spaghetti, rolls and butter, a bottle of sake, salad, and cheese and crackers.

Extremely well-known, but that doesn't take away from the effectiveness of Swift's satirical suggestion that the way for the Irish to beat their poverty was to sell their children to the rich as meat and leather.

The best essays, like Swift's, use wit – not just to sugar the pill of heavy prose, but also to ramp up the argument beyond the merely prosaic statement of a thesis.

Paine's pamphlet, anonymous at the time of publication, had a direct effect on the Declaration of Independence.

An argument in the real sense of an argument, it's as if Paine is shouting at you as he rips into the unfairness of a king on one island ruling a continent on the other side of an ocean: "If we will suffer ourselves to examine the component parts of the English Constitution, we shall find them to be the base remains of two ancient tyrannies, compounded with some new Republican materials."

The course of a couple of centuries often turns writing a bit Olde Worlde and quaint. Not here.

For all his reputation as the planet-sized brain of the 20th century, Isaiah Berlin was better at the short sprint than the magnum opus. His lectures stick in the minds of those who heard them half a century ago. This essay is just as memorable.

The inspiration came from the Ancient Greek idiom: "The fox knows many things, but the hedgehog knows one big thing."

Berlin then sifts through his storage room of a brain to divide writers into one or the other category. Tolstoy, who forms the heart of the essay, wanted to be a hedgehog but was really a fox. Other foxes include Aristotle, Montaigne and Shakespeare. Plato and Proust are hedgehogs.

All a bit reductive perhaps, but really enjoyable, and a useful boilerplate when it comes to considering the ideas of other writers.

Normally, a newspaper comment piece would never be long, or substantial, enough to constitute an essay. But this article – justifying the appointment of Jeffrey John, the Dean of St Albans, as Bishop of Reading – went way beyond tomorrow's-chip-wrapper material. The personal anecdote and light, jokey manner disguise serious thought and a deeply convincing argument; and the article becomes an essay.